DNR NextGeneration Hydrography - DNR Watercourses derived from LiDAR

This dataset contains linear features representing <b>watercourse segments generated from a LiDAR-derived DEM</b> (Digital Elevation Model). Features are defined from confluence-to-confluence and have accurate flow direction. Watercourse IDs (DNR Kittle Numbers) are currently being added so that measured watercourse routes can be generated. Data is currently available for DNR Major Watersheds #1 - Lake Superior North <i>(HUC8 04010101 Baptism-Brule)</i> and #2 Lake Superior - South <i>(HUC8 04010102 Beaver-Lester)</i> only.<br/><br/>Recent efforts by the <b><i>DNR Geospatial Water Resources Team (gWRT)</i></b> http://www.dnr.state.mn.us/watersheds/wrt.html have focused on the development of methodology to <b>derive new hydrography</b> (i.e., watercourses, watershed boundaries)<b> from LiDAR</b> data sources. The increased level of detail, accuracy and currentness of the LiDAR elevation data produces features that much better reflect the current hydrography of Minnesota's landscape. This is the first vector product generated from LiDAR for inclusion into <b>MNDNR's NextGeneration Hydrography</b> dataset. <br/><br/><b>SCALE</b><br/>The <b>Category 1</b> features in this dataset correspond, approximately, to DNR 24K (1:24,000) scale hydrography features and generally represent perennial and intermittent streams and ditches (although stream types haven't been determined for LiDAR-derived watercourses). A flow accumulation threshold value >= 10,000 m was used to extract these linear features from a hydrologically-modified LiDAR-derived 1m DEM (hDEM). This is equivalent to a drainage area of ~ 2.47 acres. Additional water conveyance features and flow paths were derived which meet smaller flow accumulation threshold values, although these categories are not yet complete. See <b>Contact Person Information</b> (below) for information about these additional features.<br/><br/><b>CARTOGRAPHIC REPRESENTATION</b><br/>The data is presented in both original (unsmoothed) and smoothed versions. The smoothing process used was <i>ArcToolbox: Cartography: Generalization: Smooth Line (PAEK method, 5m tolerance)</i>. This tool removes sharp angles in linear features (from the raster to vector conversion process) to improve <b>cartographic quality</b>. Users should note that the smoothing process can potentially move or reshape a watercourse feature in such a way that it no longer matches the original LiDAR source. A small tolerance limit (5m) was used here to minimize such errors. Results indicate that the smoothing process reduced feature lengths across the two major watersheds by a mean percentage of - 6.51% (loss). To retain true watercourse lengths for calculations, etc., the [LENGTH_MI] attribute gives the length of the original UNSMOOTHED linear feature. The [SMOOTHED_MI] attribute gives the length of the smoothed feature, while the [PERCENT_CHNG] field provides the percentage change (loss) in length due to the smoothing process.<br/><br/><b>FUNDING</b><br/>This project was funded in part by the Coastal Management Act of 1972, as amended, by NOAA's Office for Coastal Management in cooperation with the Minnesota Department of Natural Resources - Minnesota's Lake Superior Coastal Program.<br/><br/>These environmental data and related items of information have not been formally disseminated by NOAA and do not represent and should not be construed to represent any agency determination, view, or policy.<br/><br/>This project was funded in part by the Minnesota Pollution Control Agency through the Clean Water Fund from the Clean Water, Land and Legacy Amendment.<br/><br/>This project was coordinated to support the 2015 Lake Superior Lakewide Action and Management Plan (LAMP) goals under High Quality Habitats, "Integrate spatial data standards and methodologies to identify and prioritize sites for habitat protection and rehabilitation and develop targeted geomatics products for lakewide action and management."<br/><br/><b>Moving Forward (2017): </b> The gWRT is currently seeking funding to continue generation of LiDAR-derived hydrography across the state.